U.S. patent number 4,531,649 [Application Number 06/602,686] was granted by the patent office on 1985-07-30 for molded plastic cap with sealing liner.
This patent grant is currently assigned to Anchor Hocking Corporation. Invention is credited to Robert W. Shull.
United States Patent |
4,531,649 |
Shull |
July 30, 1985 |
Molded plastic cap with sealing liner
Abstract
A molded plastic closure cap has a number of downwardly
projecting fins on the underside of its cover for forming a seal
with a container in combination with a liner positioned between the
fins and the container rim. The liner is a laminated one consisting
of a plastic foam layer engaging the fins, an adhesive layer
engaging the package and a thin aluminum foil layer sandwiched
between the foam layer and the adhesive layer.
Inventors: |
Shull; Robert W. (Lancaster,
OH) |
Assignee: |
Anchor Hocking Corporation
(Lancaster, OH)
|
Family
ID: |
24412370 |
Appl.
No.: |
06/602,686 |
Filed: |
April 23, 1984 |
Current U.S.
Class: |
215/232; 215/342;
215/347; 215/351; 215/DIG.1 |
Current CPC
Class: |
B65D
41/0428 (20130101); B65D 41/045 (20130101); B65D
51/20 (20130101); Y10S 215/01 (20130101); B65D
2251/0015 (20130101); B65D 2251/0093 (20130101) |
Current International
Class: |
B65D
41/04 (20060101); B65D 51/18 (20060101); B65D
51/20 (20060101); B65D 053/04 () |
Field of
Search: |
;215/232,329,341,342,349,351,DIG.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
933489 |
|
Sep 1973 |
|
CA |
|
955886 |
|
Oct 1974 |
|
CA |
|
850871 |
|
Sep 1939 |
|
FR |
|
Primary Examiner: Norton; Donald F.
Attorney, Agent or Firm: Stoll, Wilkie, Previto &
Hoffman
Claims
Having thus described my invention, I claim:
1. An improved closure cap for forming a seal on a container
sealing surface including an irregular sealing surface of a
container comprising the combination of a molded closure shell
having a cover and a depending skirt with container engaging thread
means on the interior of said skirt, and a downwardly projecting
sealing fin means molded integrally with the shell on the underside
of the shell cover, and a sealing liner positioned within said
shell for engaging the container sealing surface with its lower
surface and the sealing fin means with its upper surface, said
sealing fin means comprising a plurality of circular fins with a
radially outermost fin being larger than the remaining fin or fins
and being flared outwardly and positioned to force the outer edge
of said sealing liner around the corner of the container finish,
and said sealing liner comprising a plurality of layers including a
soft plastic layer for engaging said sealing fin means and an
adhesive bottom layer for adhering the liner to the container
finish.
2. The closure cap as claimed in claim 1 in which said soft plastic
layer comprises polystyrene.
3. The closure cap as claimed in claim 1 which said soft plastic
layer comprises foam plastic.
4. The closure cap as claimed in claim 1 in which said sealing
liner comprises an uppermost foam plastic layer, an intermediate
aluminum foil layer, and a lowermost adhesive layer.
5. The closure cap as claimed in claim 1 in which said adhesive
bottom layer comprises a heat sensitive layer.
6. The closure cap as claimed in claim 1 in which said adhesive
bottom layer comprises a layer of high molecular weight ethylene
and vinyl acetate copolymers.
7. The closure cap as claimed in claim 1 in which said adhesive
layer comprises a pressure sensitive adhesive.
8. A sealed package comprising the combination of a container
having an irregular sealing surface, a molded closure shell having
a cover and a depending skirt with container engaging thread means
on the interior of said skirt engaging threads on the container, a
downwardly projecting sealing fin means molded integrally with the
closure shell on the underside of the shell cover, and a sealing
liner positioned within said shell engaging the container sealing
surface with its lower surface and the sealing fin means with its
upper surface, said sealing fin means comprising a plurality of
fins with the radially outermost fin being larger than the
remaining fin or fins and being flared outwardly and forcing the
outer edge of said sealing liner around the corner of said
container finish, and said sealing liner comprising a plurality of
layers includiing a soft plastic layer for engaging said fin means
and an adhesive bottom layer for adhering the liner to the
container finish.
9. The package as claimed in claim 8 in which said soft plastic
layer comprises polystyrene.
10. The package as claimed in claim 8 in which said soft plastic
layer comprises foam plastic.
11. The package as claimed in claim 8 in which said sealing liner
comprises an uppermost foam plastic layer, an intermediate aluminum
foil layer, and a lowermost adhesive layer.
12. The package as claimed in claim 8 in which said adhesive bottom
layer comprises a heat sensitive layer.
13. The package as claimed in claim 8 in which said adhesive bottom
layer comprises a layer of high molecular weight ethylene and vinyl
acetate copolymers.
14. The package as claimed in claim 8 in which said adhesive layer
comprises a pressure sensitive adhesive.
15. The package as claimed in claim 8 in which said container
comprises molded plastic.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a molded plastic closure and in
particular to such a closure having a sealing means comprising
molded plastic fins and a laminated cap liner. More particularly,
the closure includes a downwardly projecting fin means having a
generally triangular cross-section on which a laminated liner
including a plastic layer is positioned. The seal is made between
the liner and the package rim with the plastic closure ribs
engaging a resilient layer on the liner for pressing the liner into
tight sealing engagement with the container rim.
There are a number of molded closures using differently shaped and
positioned fins for sealing containers such as glass and plastic
bottles and the like. Such caps have been found to seal effectively
on containers having relatively smooth rims or sealing finishes.
There are, however, a number of containers and particularly thin
molded plastic containers which are formed with significant mold
marks or mold lines which extend over the package rims or sealing
surfaces. Difficulty has been encountered in obtaining an
inexpensive closure of the plastic type for effectively sealing
these containers such as for forming an air tight seal on such
packages. The fin and liner design in accordance with the present
invention overcomes this problem and provides for an effective,
easily applied, closure for sealing this and other packages.
Accordingly, an object of the present invention is to provide an
improved molded plastic closure and liner combination.
Another object of the present invention is to provide an improved
closure for sealing containers with projections on the container
rim or sealing surface.
Another object of the present invention is to provide a molded
plastic closure with a liner for sealing containers having uneven
or marked sealing surfaces.
Another object of the present invention is to provide an improved,
inexpensive plastic closure with liner for sealing on irregular
surfaces.
Other and further objects of the present invention will become
apparent upon an understanding of the illustrative embodiments
about to be described, or will be indicated in the appended claims,
and various advantages not referred to herein will occur to one
skilled in the art upon employment of the invention in
practice.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention has been chosen for
purposes of illustration and description and is shown in the
accompanying drawings, forming a part of the specification,
wherein:
FIG. 1 is a side elevational view of a package sealed with the
closure of the invention.
FIG. 2 is an exploded perspective view of the closure of the
invention and a package to be sealed by the closure.
FIG. 3 is a top plan view of the package of FIG. 2.
FIG. 4 is an enlarged framentary cross-sectional view of a liner in
accordance with the present invention.
FIG. 5 is a perspective view of a liner in accordance with the
invention applied to a container.
FIG. 6 is a sectional view taken along line 6--6 on FIG. 5.
FIG. 7 is an enlarged sectional view of the closure and liner with
a typical package.
FIG. 8 is an enlarged cross-sectional view of a package sealed with
the closure of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The molded portion of the plastic closure 1 comprises a cover 2 and
a depending skirt 5 with the container engaging threads 4 molded on
the inner surface of the closure skirt 5. Suitable gripping knurls
6 are formed on the upper portion of the cap skirt 5. A number of
downwardly projecting sealing fins 7 are provided on the underside
of the cap cover 2. In the preferred embodiment, the fins comprise
a number of fins 7 having a generally triangular cross-section with
the pointed ends being positioned lowermost. The radially outermost
of the sealing fins 7 preferably slants outwardly such as about at
a 45.degree. angle to the vertical and is so positioned that its
lowermost portion is positioned above the corner of the container 8
being sealed. The additional and radially inner ribs are shorter
and have a generally corresponding angle with respect to the
vertical.
As will be described below, the sealing fins 7 cooperate with
applicant's preferred sealing liner 9 in the initial sealing of the
container 8. This cooperation is provided by the partial
penetration of the fins 7 into the upper surface of the sealing
liner 9 and particularly into a soft upper layer 10 of the liner 9.
The sealed position of the package is best illustrated in FIGS. 1
and 8 and particularly in FIG. 8 where the position of the sealing
liner 9 on the container 8 finish 11 is illustrated together with
the engagement of the sealing fins 7 with the liner 9. The larger
fin 7 is imbedded in the liner 9 forcing it over the edge of the
container 8 finish 11. The closure cap 1 is tightly held in this
sealed position as its threads 4 engage cooperating threads 12
formed at the neck of the container 8.
The preferred liner 9 has a laminated construction preferably
comprising three layers. The uppermost layer 10, as illustrated in
FIG. 4 is soft plastic foam such as a polystyrene foam. This layer
having a depth about 0.02 inches is applied over a thin paper
backed aluminum foil layer 12 of about 0.0035 inches. The lowermost
layer 13 is an adhesive layer utilizing a heat sensitive adhesive
such as 1.5 to 3.0 mils. of high molecular weight ethylene and
vinyl acetate copolymers, or a pressure sensitive adhesive which
adheres the liner 9 tightly to the top of the container finish 11
as illustrated in FIGS. 5 through 8. The liner 9 may be
pre-assembled within the closure 1 so that it is applied at the
same time as the closure 1. Where a heat sealing liner is used, the
heat is applied after the cap has been screwed onto the container
as through induction heating.
When the cap 1 is removed, the liner 9 remaining attached to the
container 8 and is exposed to the user. After the liner 9 has been
torn off, the package 8 may be resealed taking advantage of the
seal provided between the molded plastic fins 7 and the container
rim 11.
The closure 1 with the liner 9 is particularly effective in sealing
containers having slight imperfections on their sealing surface,
such as illustrated by a line or flaw at 14 in FIGs. 2 and 6. The
molded plastic container 8 has a part or mold line 14 formed during
the container formation. The line 14 inteferes with proper seals in
the case of most closures, however, its adverse sealing effects are
overcome using the closure 1 through the combined action of the
liner 9 and the ribs 7 in the manner illustrated in FIG. 6. The
same advantages are obtainable with containers other than the thin
walled molded container 8 illustrated as the combination of the cap
1 and liner 9 as described overcomes minor flaws or other uneven
surfaces at the container rim 11.
It will be seen that an improved closure cap has been provided
comprising the combination of a molded closure cap with sealing
fins and a cooperating laminated liner. The cap is particularly
effective in the sealing of containers wherein irregularities at
the sealing surface result from the method of container manufacture
or from minor imperfections in the container as manufactured.
As various changes may be made in the form, construction and
arrangement of the invention and without departing from the spirit
and scope of the invention, and without sacrificing any of its
advantages, it is to be understood that all matter herein is to be
interpreted as illustrative and not in a limiting sense.
* * * * *